The production of hydrocarbons from some reservoirs has been difficult. In particular, “light tight oil” may be difficult to extract due to low formation permeability. For example, tight oil might be trapped in shale formations, which have low porosity and low permeability.
Some attempts to recover hydrocarbons from reservoirs have involved flooding, using water, steam, or carbon dioxide. However, such techniques have not widely been used for recovery of light tight oil. Such flooding may involve moving the oil toward a collection conduit, such as a production well, borehole, or fracture connected to a borehole. A sweep fluid may be injected into an injection well for production via different well(s). The wells may be completed with a single vertical fracture.
The injection of steam or hot gas has been used in heavy oil production. The steam heats the heavy oil, reducing viscosity and allowing the oil to flow from the formation.
U.S. Pat. No. 3,938,590 describes a process of introducing an oxidizing gas into a zone of increased gas permeability causing a reaction to occur, then introducing an alkalinity agent, then introducing steam in either a push-pull process or a multi-well throughput process of recovering petroleum.
U.S. Pat. No. 5,131,471 describes introduction of a heating drive fluid into a formation and simultaneous flow of a produced fluid from the formation in a single wellbore. The drive fluid exits an injection perforation and the formation fluid enters a production perforation. The production perforation is further along the wellbore than the injection perforation.
U.S. Pat. No. 5,148,869 describes the circulation of steam and a gas soluble in hydrocarbonaceous fluids into the wellbore below reservoir pressure through an upper perforated conduit of a horizontal wellbore. The steam heats the reservoir while gas enters the hydrocarbonaceous fluid, causing the hydrocarbonaceous fluids to flow around the horizontal wellbore for production by a lower conduit in the horizontal wellbore.
U.S. Pat. No. 5,503,226 describes the use of hot gas injected to heat matrix blocks and create or enlarge a gas cap, maintaining the flowing pressure in one or more production wells at a value slightly less than the free gas pressure at the gas liquid interface.
U.S. 2011/0127033 describes the use of steam injected into upper and lower fractures in a vertical wellbore prior to steam injection in the upper fracture coupled with heavy oil production from lower fractures.